That's why you're not a Firefox fan lol. I was asking because any version before 7 as far as i've tried failed for performance. What they did was they went for the visuals that chrome had with simplicity, but the performance suffered, and they only recently recovered from that "mistake" in version 7 as far as i've seen. (I've never tried v6 though, so I can't speak on it's behalf.)
As soon as I installed 7, the performance was just as fast as chrome from my comparison, and at first my assumption was because I had almost no compatible plugins, but after I modified them all to work with v7, the performance stayed at the same level it was at when I had only 1 or 2 plugins running. So far v9 doesn't seem to be much slower than chrome either. I would say it's faster than chrome honestly.
One bug in chrome i've noticed though:
But other than that, it's amazing. They did well, and i'm not bothered by that missing favicon up there.